Experimental and Computational Study of Modified Biopolymer Xanthan Gum with Synthetic Vinyl Monomers for Enhanced Oil Recovery

Abstract

Utilizing xanthan gum, a biodegradable polymer, in enhanced oil recovery (EOR) is imperative wherever there is a need for innovation in oil production that is both cost-effective and environmentally friendly. Xanthan, chosen for its natural sourcing, availability, controllability, eco-friendliness, and biodegradability, proves resilient against harsh reservoir conditions owing to its rigid structure and elongated polysaccharide chains. This study investigates two modified xanthan gum composites, achieved by grafting with synthetic vinyl monomers through emulsified polymerization. Spectroscopic characterization using FTIR and ¹H-NMR, along with surface morphology analysis via atomic force microscopy (AFM) and thermal behavior screening through TGA analysis, elucidates the properties of these modified composites. Rheological behavior under reservoir conditions, including stress scanning and viscosity/shear rate dependency, was evaluated. Material modeling with the Materials Studio program simulated the equilibrium adsorption of xanthan and modified biopolymer chains on SiO₂-quartz crystal to assess wettability alteration. Simulation results indicate that XG-g-AM, MMA&TEVS exhibit greater stability and surface coverage with more negative electrostatic energies compared to XG and XG-g-AM&MMA. The laboratory runs on a sandstone-packed model to identify the disclosed XG-g-AM&MMA and XG-g-AM, MMA&TEVS biopolymers as promising EOR candidates and wettability modifiers in challenging sandstone reservoirs, as per experimental outcomes.